It is known that internal combustion engines are equipped with a cooling system. The cooling system is generally provided for cooling down the internal combustion engine, as well as other engine fluids, such as for example the exhaust gas in the EGR cooler and/or the lubricating oil in the oil cooler.
The cooling system schematically includes a coolant pump that delivers a coolant fluid, typically a mixture of water and antifreeze, from a coolant tank to a plurality of cooling channels internally defined by the engine block and the cylinder head and forming a so-called cylinder water jacket.
Once the coolant is circulated through a cylinder water jacket, it may be diverted to another portion of the internal combustion engine, namely the cylinder head, to remove additional excess heat or it may be pumped to a heat exchanger where heat is removed from the coolant prior to being returned to the engine.
In a known embodiment, a cylinder block of an internal combustion engine has an inner side wall defining the cylinder bores and an outer side wall surrounding the inner side wall. A cylinder block water jacket is defined by the inner side wall and the outer side wall. A cooling water inlet is formed in one end of the cylinder block. Cooling water flows through the cooling water inlet into the cylinder block water jacket. The cooling water supplied through the cooling water inlet into the cylinder block water jacket is divided into two cooling water streams, one for each side of the cylinder block, by means of two side passages through which the cooling water flows in a longitudinal direction from the cooling water inlet to a cooling water outlet.
Known water jackets for internal combustion engines leave open a series of issues. A first issue is that the coolant flows in the engine block on both sides of the cylinder head, namely the intake and exhaust side, leading to difficulties in managing and calibrating both coolant flows in the deck cooling area, in order to have good balancing among cylinders. Furthermore, known water jackets are penalized by a high pressure drop and need a significant volume of coolant to operate properly. Finally, known water jackets may be costly to produce due to casting and manufacturing difficulties.